Electrostatic ironing apparatus



Sepvt.' 14. 1948- E; c. PITMAN ETAL. 2,449,318

ELECTRQSTATIC IRONING APPARATUS Filed April 18, 1944 fzven'or Eaae C. Pa

Erl/wzl. @ra/2M by @wwf A521029@ Patented Sept. 14, ,1948

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Crandell, "WllesleyjMass assignors4 toConpo *f ShoeMachinery"Corporation, Boston,fMa`s's.,fa

corporation =off Delaware Application April 18, 1944,- `Serial No.5312532" 4 Claims.

1 This invention relates to'electrostatic heating apparatus and relatesmore particularly to'hand irons providing electrostatic heat forpressing and a dampoloth, the cloth is a dielectric in theelectro'static fields and byhysteiesisfaction, is heated. The powerabsorbed'byrthe clothl from the electrostatic fields and` therefore, theheat produced in' the elothl` is :proportional-tothe moisture content ofthe cloth. Therefore since the heatv produced varies in accordance withthe dampness of the cloth, as the cloth is dried by the application ofthe iron, the heat-becomes less and less until when the cloth iscompletely dry, relatively no heat is produced.

The ironing surface of the iron is not heated so that it may be leftupon the surface of the cloth being ironed, for any period of time with=out any scorching or burning of the cloth.

The iron is designed for use with vanironing board or table preferablyhaving a metallic ply formed in its supporting surface. This metallicply forms a free electrode which is capacity coupled. to the electrodesin the iron, when the iron is placed upon the table, the electricalcapacity between the free electrode and the electrodes in the iron beinggreater than the capacity between the alternately connected electrodesin the iron. The effective electrostatic field is, therefore, providedto a major extent between the free electrode and the other electrodes.By providing such a free electrode, the size of the hand iron may bereduced considerably over that which would be necessary were the freeelectrode not provided, and lower voltages may be supplied to theelectrically connected electrodes.

The free electrode since not being connected in the electrical circuit,may be grounded so that no electrical charges may be induced upon itssurface.

An object of the invention is to provide electrostatic heat with a handiron.

Another object of the invention is to utilize a metallic clothsupporting surface as a free electrede and to utilize electrodes in ahand iron 2f. connected `to a 'high 'frequency' 'oscillatory' for"heating. the `cloth with Velectrostatic heat.-

The invention will'now be described with refer-ff encetothe drawing; ofwhich:

Figli isa projected view of" an ironing table" having; va high frequency`oscillator 'contained-e therein, and of a hand-ironhavin'gelectrodesffin its base connected to the oscillator; the table'liaw'`ing 'a metal ply; andv Figyz is a sectional `View alonglthelinesff2-`2cfi Fieri.

The table 4illustrate'ci'by Figgl hasthe -doors Ill which yprovideaccess tofthel oscillator'l I supporte f edI inthe .interior ofA thetable.-'llie oscillator I I* `lis`"a conventional'- oscillator-utilizingelectronic.y

tubes-ior lproducing high frequency alternating i currentv which, forexample;4 may be'twenty meg-atil cycles" The table top I-'2=' has *ametallic ply f I3-1which 'in f; ironing-'acts'v as a freeelectrode asnwill bei` de:A scribed.

The hand iron Ill has in its base, the metallic electrodes I5, which areconnected to each other and to one side of the oscillator II, and themetallic electrodes I6 which are connected to each other and the otherside of the oscillator. The electrodes I5 and I6 are parallel and extendcrosswise the iron with their lower surfaces parallel to the lowersurface of the iron. The electrodes I5 are arranged alternately with theelectrodes I6 so that they may be considered as interlaced.

The body and handle of the iron should be of non-metallic material foravoiding the production of electrostatic charges thereon,

When a damp cloth is placed on the table top I2 and the oscillator I Iis energized and the iron I4 pressed against the cloth, electrostaticelds are produced between the electrodes I5 and I6 and the metallic plyI3 below the surface I2 acting as a free electrode capacitively coupledto the electrodes I5 and I6. The electrostatic fields produce heat inthe cloth so that the cloth may be ironed by movement of the hand ironI4 in the usual manner.

It is preferred that the oscillator Il be of the push-pull typedisclosed in the E. L, Crandell, U. S. Patent No. 2,298,038. With thistype of oscillator, a free electrode is maintained at ground potentialso that there can be no voltages induced in the table top I2 and no harmcaused by electrical shock, to the operator of the iron.

While one embodiment of the invention has been described for the purposeof illustration, it should be understood that the invention is notlimited to the exact apparatus and arrangement of apparatus disclosed asmodifications thereof may be suggested by those skilled in the artwithout departure from the essence of the invention.

What is claimed is:

1. Ironing apparatus comprising in combination, a hand ironer having abody portion of non-metallic material, a plurality of spaced electrodesembedded within the body portion of said ironer, an oscillator, meansconnecting said electrodes to Said oscillator, a cabinet housing saidoscillator, and means forming a portion of said cabinet providing asurface for supporting the material to be ironed and providing a freeelectrode capacitively coupled to said electrodes when said ironer isplaced upon said material.

2. Ironing apparatus comprising in combination, a hand ironer having abody portion of nonmetallic material, a plurality of interlaced, spacedelectrodes embedded within the body portion of said ironer, a pair ofelectrical conductors connecting alternate of said electrodes together,an oscillator, means connecting said conductors to said oscillator, acabinet housing said oscillator, and means forming a portion of saidcabinet providing a surface for supporting the material to be ironed andproviding a free electrode capacitively coupled to said electrodes whensaid ironer is placed upon said material.

3. Ironing apparatus comprising in combination, a hand ironer having abody portion of non-metallic material, a plurality of interlaced spacedelectrodes embedded within the body portion of said ironer, a pair ofelectrical conductors connecting alternate of said electrodes together,an oscillator, means connecting said conductors to the output circuit ofsaid oscillator, a cabinet housing said oscillator, said cabinetproviding a surface for supporting the material to be ironed, and meanslocated below said supporting surface providing a free electrodecapacitively coupled to said electrodes when said ironer is placed uponsaid material.

4. Ironing apparatus comprising, an oscillator,

a housing for said oscillator, a slab-like support providing an ironingsurface, said housing being disposed immediately below and attached tothe under side of said support, a hand ironer having a body portion ofnon-metallic material, a plurality of spaced electrodes embedded Withinthe body portion of said ironer, means connecting alternates of saidelectrodes to opposite sides of the output circuit of said oscillator,and means located below the ironing surface of said slab-like supportand providing a free electrode capacitively coupled to said electrodeswhen said ironer is brought into ironing Contact with material placedupon said support.

EARLE C. PITMAN.

ERVIN L. CRANDELL.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,484,879 Fogwell et al Feb. 26,1924 2,133,494 Waters Oct. 18, 1938 2,137,189 Whitman Nov. 15, 19382,298,038 Crandell I Oct. 6, 1942 2,332,468 Lofgren Oct. 19, 19432,342,846 Crandell II Feb. 29, 1944 FOREIGN PATENTS Number Country Date518,691 Great Britain Mar, 5, 1940 OTHER REFERENCES Taylor, John PI.,Electronics magazine, November 1943, pages 10G-7.

